Tuesday, December 13, 2011

Cuckoo for Cocoa Puffs?

A visit to Jelly Belly heaven....

will I be paying for this later?

One of the enduring myths of Christmas (aside from the man with the bag) is that eating all those candy canes will make your kids go bonkers. There are certainly observational studies showing that sugar ingestion leads to inattention and impulsivity. But if you look at only the well-designed, double-blind, placebo-controlled studies (there have been at least a dozen), not one has found that sugar has a deleterious effect on behavior in kids, even in those with attention deficit-hyperactivity disorder (ADHD).

The definitive study was performed in normal preschoolers, as well as 6- to 10-year olds whose parents had identified as being "sugar sensitive." The care involved in the design of this trial was remarkable. A dietician supervised the removal of all the food from the home, except for coffee and alcohol "as long as they were not consumed by the children." The families were then provided with meals for the next 9 weeks. The experimental diets, which rotated every three weeks, included one that used sucrose (sugar) as a sweetener, one that used aspartame (Nutrasweet), and one that used saccharin. The families were not told the hypothesis, or what substitutions were made. In fact, the investigators created sham diets that changed every week, to throw the parents off the scent. One sham diet, for instance, consisted mainly of red and orange foods (although no artificial food coloring or additives were allowed). Every three weeks, children underwent tests of their memory, attention, motor skills, reading and math performance. Interviewers also surveyed parents and teachers about their kids' behavior.

The blinding was near perfect; only one parent correctly identified the sequence of diets. Even though 48 tests and surveys were conducted per child, almost none found a difference in cognition or behavior among the three diets. The one exception? Children on the sugar diet scored significantly better on the cognition portion of the Pediatric Behavior Scale. I'm tempted to use this as a post hoc justification for letting my kids eat Cap'n Crunch, but it's probably just a chance finding.

Nonetheless, some parents continue to insist that sweets make their kids hyper. Once you believe something, you're more likely to see it. In one study, thirty-five 5- to 7-year-old boys who were reported to be sensitive to sugar were randomized to two groups. In one group, the mothers were told their sons would receive a sugary drink; in the other group, they were told that they would receive a Nutrasweet drink. They then videotaped the boys playing by themselves and with their mom. The boys also wore an "actometer" on their wrists and ankles as an objective measure of their activity level.

Here's the twist: Both groups actually received Nutrasweet. As expected, there was no significant difference in the boys' activity levels by videotape review or actometer readings. But the mothers who thought their sons consumed sugar reported significantly more hyperactivity during the play session than those who knew they were drinking Nutrasweet. The videotape reviewers (who were blinded to the intervention) also found that the mothers who thought their boys drank sugar were more likely to hover around them, yet they scored lower in warmth and friendliness. It was kind of a mean study, if you think about it. First, they lied to the moms, then they slammed them for being more vigilant.

So why, despite the plethora of data to the contrary, has the sugar myth persisted? It's possible that something else in the sweets, such as food coloring or caffeine, causes hyperactivity. And think about it: When do we do let our kids consume copious amounts of sugar? On birthdays, Halloween, and Christmas -- all recipes for going a little nuts.

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About Me

My name is Stephanie, and I'm the happy but tired mother of two boys (ages 8 and 1) and a girl (age 6). I'm also a general internist who practices in a public teaching hospital in California, and the editor of a medical education website, ProfessorEBM.com. My passion is teaching about evidence-based medicine (EBM) to doctors-in-training. EBM involves critically reading the medical literature and applying it appropriately to patient care. I thought it would be fun and enlightening to examine firsthand the evidence on how best to parent kids. My mission is to debunk bad science and to highlight the gaps in our medical and psychosocial knowledge. But first, a warning: I don't treat children, and my take on the research may or may not apply to your particular kid. Reading this blog shouldn't be a substitute for talking to your pediatrician. Heck, I don't even follow my own advice half the time! Enjoy.